Search Results

Search found 14279 results on 572 pages for 'design choices'.

Page 465/572 | < Previous Page | 461 462 463 464 465 466 467 468 469 470 471 472  | Next Page >

• Do you use enums in your data applications and how?

  - by Ivan

  My practice shows that a general enterprise application has a lot of entities which's nature corresponds to an elementary enumeration. For example We may have an Order entity which may have such fields as "OrderType", "OrderStatus", "Currency", etc. referencing corresponding Entities which are nothing more than just a textual name bound to a key to be referenced. Using enums would look very natural here. But entities have to be defined in application code at design-time, am I right? While in we need to be able to CRUD enum value variants at runtime and use enums in server-side SQL queries (like stored procedures and views). What are you practices and thoughts on this subject? I am particularly interested in C#4, linq and T-SQL.

  Read the article

• Is this code thread-safe?

  - by mafutrct

  I've got a class with several properties. On every value update, a Store method is called with stores all fields (in a file). private int _Prop1; public int Prop1 { get { return _Prop1; } set { _Prop1 = value; Store(); } } // more similar properties here... private XmlSerializer _Ser = new ...; private void Store() { lock (_Ser) { using (FileStream fs = new ...) { _Ser.Serialize (fs, this); } } } Is this design thread-safe? (Btw, if you can think of a more appropriate caption, feel free to edit.)

  Read the article

• Button Application- iPhone Application

  - by Extremely frustrated

  I am a meganoob in iPhone Application programming. All I want to do is make an application with a single button. When you press the button, it plays an audio file. The button is just two images, one for the normal state and one for the pressed state. I have no clue how to get from point A to point B, it seems so straightforward in web design, why can't it be like that for this too? Anyone out there willing to drop some hints?

  Read the article

• Ways to call Blocks within Magento: createBlock vs Layout xml file

  - by N. B.

  Context: I'm trying to include Adminhtml blocks in the frontend of the site to replace some of the user account blocks. The first thing I'm trying to do is simply display the block on the correct page. I can replace the entire page by setting the Body of the response inside the controller, but I'm having a hard time including the block in the layout xml file and then calling it within the template. Why would I be able to create an adminhtml/sales_order_grid from Mage_Sales_OrderController using createBlock: $this->getResponse()->setBody($this->getLayout()->createBlock('adminhtml/sales_order_grid')->toHtml()); But not from a frontend layout, using a declaration <block type="adminhtml/sales_order_grid" name="orders_widget"/> within app/design/frontend/default/default/layout/sales.xml The latter produces an error without a stack trace: Fatal error: Call to a member function toHtml() on a non-object in app/code/core/Mage/Core/Model/Layout.php on line 526 Thanks for any guidance!

  Read the article

• Find all clauses related to an atom

  - by Luc Touraille

  This is probably a very silly question (I just started learning Prolog a few hours ago), but is it possible to find all the clauses related to an atom? For example, assuming the following knowledge base: cat(tom). animal(X) :- cat(X). , is there a way to obtain every possible information about tom (or at least all the facts that are explicitly stated in the base)? I understand that a query like this is not possible: ?- Pred(tom). so I thought I could write a rule that would deduce the correct information: meta(Object, Predicate) :- Goal =.. [Predicate, Object], call(Goal). so that I could write queries such as ?- meta(tom, Predicate). but this does not work because arguments to call are not sufficiently instantiated. So basically my question is: is this at all possible, or is Prolog not design to provide this kind of information? And if it is not possible, why?

  Read the article

• bad performance from too many caught errors?

  - by Christopher Klein

  I have a large project in C# (.NET 2.0) which contains very large chunks of code generated by SubSonic. Is a try-catch like this causing a horrible performance hit? for (int x = 0; x < identifiers.Count; x++) {decimal target = 0; try { target = Convert.ToDecimal(assets[x + identifiers.Count * 2]); // target % } catch { targetEmpty = true; }} What is happening is if the given field that is being passed in is not something that can be converted to a decimal it sets a flag which is then used further along in the record to determine something else. The problem is that the application is literally throwing 10s of thousands of exceptions as I am parsing through 30k records. The process as a whole takes almost 10 minutes for everything and my overall task is to improve that time some and this seemed like easy hanging fruit if its a bad design idea. Any thoughts would be helpful (be kind, its been a miserable day) thanks, Chris

  Read the article

• Which programming language to choose? (for a specific problem/domain, details inside)

  - by Bijan

  I am building a trading portfolio management system that is responsible for production, optimization, and simulation of non-high frequency trading portfolios (dealing with 1min or 3min bars of data, not tick data). I plan on employing Amazon web services to take on the entire load of the application. I have four choices that I am considering as language. a) Java b) C++ c) C# d) Python Here is the scope of the extremes of the project scope. This isn't how it will be, maybe ever, but it's within the scope of the requirements: Weekly simulation of 10,000,000 trading systems. (Each trading system is expected to have its own data mining methods, including feature selection algorithms which are extremely computationally-expensive. Imagine 500-5000 features using wrappers. These are not run often by any means, but it's still a consideration) Real-time production of portfolio w/ 100,000 trading strategies Taking in 1 min or 3 min data from every stock/futures market around the globe (approx 100,000) Portfolio optimization of portfolios with up to 100,000 strategies. (rather intensive algorithm) Speed is a concern, but I believe that Java can handle the load. I just want to make sure that Java CAN handle the above requirements comfortably. I don't want to do the project in C++, but I will if it's required. The reason C# is on there is because I thought it was a good alternative to Java, even though I don't like Windows at all and would prefer Java if all things are the same. Python - I've read somethings on PyPy and pyscho that claim python can be optimized with JIT compiling to run at near C-like speeds.... That's pretty much the only reason it is on this list, besides that fact that Python is a great language and would probably be the most enjoyable language to code in, which is not a factor at all for this project, but a perk. To sum up: - real time production - weekly simulations of a large number of systems - weekly/monthly optimizations of portfolios - large numbers of connections to collect data from There is no dealing with millisecond or even second based trades. The only consideration is if Java can possibly deal with this kind of load when spread out of a necessary amount of EC2 servers. Thank you guys so much for your wisdom.

  Read the article

• Should XML be used server-side, and JSON client-side?

  - by Michel Carroll

  As a personal project, I'm making an AJAX chatroom application using XML as a server-side storage, and JSON for client-side processing. Here's how it works: AJAX Request gets sent to PHP using GET (chat messages/logins/logouts) PHP fetches/modifies the XML file on the server PHP encodes the XML into JSON, and sends back JSON response Javascript handles JSON information (chat messages/logins/logouts) I want to eventually make this a larger-scale chatroom application. Therefore, I want to make sure it's fast and efficient. Was this a bad design choice? In this case, is switching between XML and JSON ok, or is there a better way?

  Read the article

• Designing DAL in .NET to be "data-source independent" and not just "database independent" ?

  - by Munish Goyal

  How to design such flexible DAL (specifically in .NET) ? What interfaces .NET provides and what should be done on my own ? Its a greenfield project starting with SQL Server as data source but in future, parts of it will move to different NoSQL type of datastores. Also, we may need to experiment with lot of different datastores (like some data may have to go with Cassandra, some with RDBMS, some to other DHT etc.) Therefore easily switchable access layer will be needed. All i know right now is the 'data' and 'operations needed on that data'.

  Read the article

• Browser mode and document mode in IE9

  - by Ozzone

  I use the Developer Tools in IE9 to switch between IE7, 8 & 9 Browser Modes for testing markup & CSS. I use following combinations. IE7 Browser Mode + Document mode IE7 Standards IE8 Browser Mode + Document mode IE8 Standards IE9 Browser Mode + Document mode IE9 Standards But, if i use following combination, few design's position issues are occured. IE9 Browser Mode + IE7 Standards Is the above combination valid? or Does i need to change Document mode forcefully?

  Read the article

• Linq to sql Incorrect varchar length

  - by scott

  I have a table with a nullable varchar(50) column in it. When I am updating the value through linq to sql and trace the call in profiler it is defining the parameter as varchar(36). This is obviously causing some minor issues when we are trying to insert data that is between 37 and 50 characters long. I have tried removing the table and re-adding it to the design surface but the same thing happens. I also tried removing that property and adding it manually, same issue. When I look at the designer.cs code it shows the attribute properly: [Column(Storage="_Name", DbType="VarChar(50)")] I am out of ideas, anybody seen this before? Every other column is correct.

  Read the article

• How can I dynamically inject code to event handlers in Delphi?

  - by mjustin

  For debugging / performance tests I would like to dynamically add logging code to all event handlers of components of a given type. For example, for all Dataset components located ona TDatamodule, I would like to add some code for the BeforeOpen and the AfterOpen event to store the start and end time and send a line to a logger with the elapsed time in the AfterOpen event. I would prefer to do this dynamically (no component subclassing), so that I can add this to all existing datamodules and forms with minimal effort only when needed. Iterating all components and filtering by their type is easy, but for the components which already have event handlers assigned, I need a way to store the existing event handlers, and assign a new modified event handler which first does the logging and then will invoke the original code which was already present. Is there a design pattern which can be applied, or even some example code which shows how to implement this in Delphi?

  Read the article

• is this the correct use of JavaScript or is there a better way ? jquery slide to anchor

  - by Stuart Robson

  Hi guys, I'm currently workin on a project with a one page design that'll slide up and down between sections on an link... currently i have it as home artist's materials picture framing gallery contact us or <a href="javascript:void(0)" onClick="goToByScroll('contactus')"> hope fully you can see the code... then in a js file i've got function goToByScroll(id){ $('html,body').animate({scrollTop: $("#"+id).offset().top},'slow'); } is this ok ?? or should this be done a different way ??? thanks in advance

  Read the article

• Wiki for requirements engineering

  - by Shanon

  Hi, I'm looking to to build a wiki based tool the helps/aides in the requirements engineering process. More specifically I am hoping to end up with a tool that helps inexperienced users easily create and design requirements documents on a wiki platform. I was wondering if there exist any wiki/wiki platforms that either already exist or are easily extendible or would be worth looking at that for this purpose. For instance some of the features I was hoping to add would be to add structure to a document so that information is filled out in a standardised manner. Another idea I was looking at was to somehow create relationships between different types of documents (for example- a goal diagram gets evolves/ helps in the development of the class diagram). So far I have come across FOSwiki which claims to to fully customisalble...but I'm not sure what it means and what I can really do with that. Any input on FOSwiki is also highly appreciated.

  Read the article

• Abstract class over Interfaces in ADO.Net Environment

  - by Amit Ranjan

  I am developing a web app but is not satisfied with is architecture that I am following. The architecture is plain old conventional 3 tier architecture. What i want is follow some design pattern or architecture that will be help me in decoupling my code. I have idea about MVC and MVP architectures for Web App but i need different from that. I want to use OOPS concepts using abstract classes and interfaces, polymorphism etc in my app but not MVC and MVP. I dont know why? I havent tried any ado.net application earlier via abstract class or interfaces, so i need your help. Thanks

  Read the article

• Load a UIView from a NIB

  - by Winder

  I have been using UIViewControllers and initWithNibName with much success, basically using them as a convenient way to design the view with Interface Builder. Unfortunately I have built a hierarchy of views before noticing this line in the UIViewController documentation: Note: You should not use view controllers to manage views that fill only a part of their window My question is this: Having a very simple NIB that only has a UIView in addition to the default First Responder and Owning Object, what is the simplest way to load the UIView into my code? I have not been able to get loadNibNamed:owner:options: to work at this point, but suspect the answer will involve it somehow.

  Read the article

• [C#] Async threaded tcp server

  - by mark_dj

  I want to create a high performance server in C# which could take about ~10k clients. Now i started writing a TcpServer with C# and for each client-connection i open a new thread. I also use one thread to accept the connections. So far so good, works fine. The server has to deserialize AMF incoming objects do some logic ( like saving the position of a player ) and send some object back ( serializing objects ). I am not worried about the serializing/deserializing part atm. My main concern is that I will have a lot of threads with 10k clients and i've read somewhere that an OS can only hold like a few hunderd threads. Are there any sources/articles available on writing a decent async threaded server ? Are there other possibilties or will 10k threads work fine ? I've looked on google, but i couldn't find much info about design patterns or ways which explain it clearly

  Read the article

• the best "Simple" CMS system suitable for .Net MVC

  - by Truegilly

  Hello, I'm developing a MVC .Net site and would like to implement a CMS system. So far I have looked at Umbraco, which looks good but the help is poor and the getting started video section is empty, and dotnetnuke, which again looks good but I get the impression its aimed at non developers, plus to has much more than I need and want. In my last job I created a basic custom CMS system that worked by simply adding values into the database, the application called the text from there. it worked fine but I don’t have the source code. what I'm after is a simple CMS system that really just controls text and images, I dont need all the fancy stuff thats in umbraco and dotnetnuke, all the design and CSS i can do myself. also as im working with MVC (which is awesome, and such a breath of fresh air compared to the web forms/telerik crap I have to put up with at work) it needs to be compatible. A simple CMS, can anyone provide any suggestion ? Truegilly

  Read the article

• When to use POJO and When to use SLSB

  - by user83795

  we are using EJB3 in our application. Our design aim is to separate persistence layer from Business Layer. So we have developed XXXbean classes to be used as SLSB and XXXRepository classes to be used as persistence classes. We also have POJO that implement reusable NON business logic(get list of countries etc) and we call then service/helper Classes. We use EJB3 JPA (using Hibernate provider) and Repository classes has all the methods for CRUD operation and the get methods for data access. Currently XXXRepository classes are all POJO and we instantiate these classes directly from the bean XXXClasses or from the service Objects. Should the XXXRepository classes be SLSB ? what would be the benefits and pitfalls of converting them to SLSB?

  Read the article

• Can't see or add Website Data Sources in RDLC report in ASP.NET MVC

  - by RobertC

  In the RDLC report, in Design view in Visual Studio 2008, we don't see anything in the Website Data Sources tab and the button to Add New Data Source is grayed out. Only the Refresh button is enabled, and clicking it doesn't do anything. Our business logic layer returns Lists of business objects and the business logic and business object projects are both referenced by the MVC project. This is an MVC app, so there is no App_Code folder. How do we get our business objects to appear in the Website Data Sources list so we can drag and drop fields from the object onto our RDLC report?

  Read the article

• How to Conduct an online coding competition?

  - by Alice

  I need to design a website for a programming competition event. It will be similar to TOP CODER competitions. User will be given all questions & then user submits the code, that will be running on the server and checks if it gives the correct solution or not. The first one to finish all the questions is the winner. I've no clue about how to proceed. Assume that languages that are supported are C, C++, Java.

  Read the article

• Preventing Netbeans JAXB generation trashing classes

  - by Mac

  I'm developing a SOAP service using JAX-WS and JAXB under Netbeans 6.8, and getting a little frustrated with Netbeans trashing my work every time the XSD schema my JAXB bindings are based upon changes. To elaborate, the IDE automatically generates classes bound to the schema, which can then be (un)marshalled from/to XML using JAXB. To these classes I've added extra methods to (for example) convert to and from separate classes designed to be persisted to database with JPA. The problem is that whenever the schema changes and I rebuild, these classes are regenerated, and all my custom methods are deleted. I can manually replace them by copy-pasting from a backup file, but that is rather time-consuming and tedious. As I'm using an iterative design approach, the schema is changing rather frequently and I'm wasting an awful lot of time whenever it does, simply to reinstate my previous code. While the IDE automatically regenerating the JAXB-bound classes is entirely reasonable and I don't mean to imply otherwise, I was wondering if anyone had any bright ideas as to how to prevent my extra work having to be manually reinstated every time my schema changes?

  Read the article

• Java multiline string

  - by skiphoppy

  Coming from Perl, I sure am missing the "here-document" means of creating a multi-line string in source code: $string = <<"EOF" # create a three line string text text text EOF In Java I have to have cumbersome quotes and plus signs on every line as I concatenate my multiline string from scratch. What are some better alternatives? Define my string in a properties file? Edit: Two answers say StringBuilder.append() is preferable to the plus notation. Could anyone elaborate as to why they think so? It doesn't look more preferable to me at all. I'm looking for away around the fact that multiline strings are not a first-class language construct, which means I definitely don't want to replace a first-class language construct (string concatenation with plus) with method calls. Edit: To clarify my question further, I'm not concerned about performance at all. I'm concerned about maintainability and design issues.

  Read the article

• Again, what version control system to choose?

  - by Ivan

  Please excuse me for probably a newbie hundred-times-chewed question. I have no experience with version control systems except of using Visual Source Safe in a project done by 2 people sitting in front of each other (which has shown VSS quite sack of boulders, not anything useful). Right now I am looking to grok-in using some modern VCS. Here are the preferences in descending priority order: Platform-agnostic. Pretty pleasant to use With Visual Studio 2010 on Windows as well as With NetBeans 6.9 and Eclipse 3.6 on Linux and Mac. Convenient and efficient for mutually-dependent projects done by teams of 1-10 and consisting of files of quite a diverse selection of types. Including early-stage projects with unstable design and experimenting. Modern. As fresh and future-technology-feature-rich as possible. Free & open-source. Should I take a closer look at SVN, Mercurial, GIT, Bazaar, or something else?

  Read the article

• Why are hidden fields used?

  - by Pavan Reddy

  I have always seen a lot of hidden fields used in web applications. I have worked with code which is written to use a lot of hidden fields and the data values from the visible fields sent back and forth to them. Though I fail to understand why the hidden fields are used. I can almost always think of ways to resolve the same problem without the use of hidden fields. How do hidden fields help in design? Can anyone tell me what exactly is the advantage that hidden fields provide? Why are hidden fields used?

  Read the article

< Previous Page | 461 462 463 464 465 466 467 468 469 470 471 472  | Next Page >